Author Topic: Any success with LoRa low-power listening..?  (Read 13698 times)

Jim

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Re: Any success with LoRa low-power listening..?
« Reply #15 on: October 25, 2019, 03:51:01 PM »
Hi,
I have been struggling with this topic since a year now :O

Is there a chance  to use a rfm95 in receiver with a couple of aa batteries for a couple of month?

Jim

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Re: Any success with LoRa low-power listening..?
« Reply #16 on: May 03, 2020, 05:52:26 PM »
Hi,
are there are any news about it in the meanwhile? Still looking for a solution in 2020 and would be happy for a few words or hints.
I'm looking for a battery powered (max 4 AA batteries) receiver with a responds time of approx 2ms that is able to receive a data word of 8 or 9 bits. Operation time should be around 6month with those batteries.
Is there any chance to do it?

Felix

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Re: Any success with LoRa low-power listening..?
« Reply #17 on: May 03, 2020, 09:01:03 PM »
2ms? No. A roundtrip of packets will take longer, and thats if your node is actively listening.

Jim

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Re: Any success with LoRa low-power listening..?
« Reply #18 on: May 16, 2020, 04:33:43 AM »
incognito wrote something about 2ms. If that's nno possible in the meanwhile I would also be happy with 5ms. That would be great. I'm trying to figure out what is possible in terms of speed and lowest consumption

Felix

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Re: Any success with LoRa low-power listening..?
« Reply #19 on: May 17, 2020, 10:03:18 PM »
If you are looking for copy-paste code that works I'm sorry I'm afraid I don't have that to provide.
But please see this thread where a long discussion on increasing throughput with MoteinoM0 took place. Reading that might be eye opening for reaching your goals or providing some answers, there's some sample code there too.

IMO to get into the lower ms transmissions with RFM69/FSK, is possible. For that purpose, forget LoRa.
You will likely have to take a deep dive into the registers of the RFM69 and walk through the library a bit to understand how a packet is formed and transmitted. Then turn off all features like encryption which add extra processing time. Increase bitrate to the maximum 300kbps. See some examples in RFM69 library to set that up, or at the thread above I believe there is some posted as well.

Keep packets to an absolute minimum length. Use a logic analyzer (to analyze the SPI data) and/or CurrentRanger and measure your packets precisely. You will need a lot of patience, but it's very gratifying work when you chase a specific performance aspect out of the RFM69.